Radiosynthesis of no-carrier-added meta-[124I]iodobenzylguanidine for PET imaging of metastatic neuroblastoma

Meta-iodobenzylguanidine (mIBG) has been radiolabelled at the no-carrier-added level with [124I] for a proof of concept study to assess the diagnostic accuracy of [124I]mIBG PET/CT in detecting metastatic deposits in patients diagnosed with metastatic neuroblastoma. Radiolabelling of mIBG was achieved via the iododesilylation reaction between [124I]sodium iodide and meta-trimethylsilylbenzylguanidine. [124I]mIBG was produced in 62-70 % radioiodide incorporation yield from [124I]sodium iodide. The average amount of formulated [124I]mIBG was 359 MBq (range 344-389 MBq) with an average specific radioactivity of 4.1 TBq μmol-1 (range 1.8-5.9 TBq μmol-1) at end of synthesis.